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COLORATION                                            1 1

be  called  brightly coloured.     The Bats   of the  geims
have been compared to large butterflies, and some  of the JBlyiiig:
Squirrels have strongly-marked contrasts of reddish brown, wlifte,
and   yellow.    The   same   may   be   said   of the  spines  of certain
Porcupines.     But we find in the hair 110 bright blues, greens, and
reds such as are common among birds.
There are certain general facts about the coloration of
mammals which require some notice here. Next to the
usually sombre hues of these animals the general absence
of secondary sexual coloration is noteworthy. In but a few
cases among the Lemurs and Bats do we find any marked
divergences in. hues between males and females. Secondary
sexual characters in mammals are,, it is true, often exhibited
by the great length of certain hair -tracts in the male, such as
the mane of the Lion, the throat- and leg-tufts of the IBar-
bary Sheep, and so forth ; but apart from these, the secondary
sexual characters of mammals are chiefly shown in size, e.g. the
Gorilla, or in the presence of tusks, e.g. various Boars, or of horns, as
in tbe .Deer, etc. The coloration of mammals frequently exhibits
conspicuous patterns of marking. These are in the form, of
longitudinal stripes, of cross-stripes, or of spots ; the latter may
be " solid " spots, or broken up, as in the Leopard and Jaguar,
into groups of smaller spots arranged in a rosette-fashion. "We
never find in mammals the complicated " eyes " and other mark-
ings which occur in so many birds and in other lower Verte-
brates. It is important to note that in tlie Mammalia whose
sense of sight is quite keen there should be a practical absence
of secondary sexual colours. As to the relationship of the various
forms of marking that do occur, it seems clear that there has
been a progression from a striped or spotted condition to uniform
coloration. For we find that many Deer have spotted young ;
til at the young Tapir of the New World is spotted, while its
parents are uniform blackish brown ; the strongly -marked spot-
ting of the yoxing Puma contrasts with the uniform brown of the
adult ; and the Lion cub, as every one knows, is also spotted, the
adult lioness showing considerable traces of the RpotR.
The seaBonal change in the colours of certain mammals is a
subject upon which much has been written. The extreme of this
in Been iu those creatures, such as the Polar Hare and the Arctic
Fox, which become entirely blanched in the winter, recovering